The present invention is directed to a prosthesis or implant for use as an intervertebral disc prosthesis having a first member having a first area, groove or channel, a second member having a second area, groove or channel, and a ball bearing for situating in said first and second area, groove or channels.
In cases where intervertebral disc tissue is removed or is otherwise absent from a spinal segment, corrective measures are indicated to insure proper spacing of the vertebrae formally separated by the removed disc tissue. Commonly, the two vertebrae may be fused together using transplanted bone tissue, and artificial fusion element, or other compositions or devices. Unfortunately, spinal fusion has several drawbacks, including preventing the fused vertebrae from moving rotationally or translationally with respect to each other, as natural disc tissue permits. The lack of mobility may increase the stresses on adjacent spinal motion segments.
Several types of inter-vertebral disc arthroplasty devices have been proposed for overcoming some of the problems of the past, and these devices include the devices shown in U.S. Pat. Nos. 4,528,990; 4,760,851; 5,203,346; 5,314,477; 5,556,431; 5,582,186; 5,648,296; 5,683,465; 5,755,796; 5,782,832; 5,850,836; 5,895,428; 5,954,674; 6,001,130; 6,019,792; 6,063,121; 6,113,637; 6,179,874; 6,228,118; 6,473,717; 6,540,785; 6,562,045;. 6,666,579; 6,682,562; 6,733,532; 6,764,515; 6,770,095; and U.S. Publication Nos. 2004/0024462; 2004/0073310; 2004/0111157; 2004/0176844; 2003/0233146; and 2004/0133278.
What is needed therefore is an improved prosthetic implant that overcomes some of the deficiencies of prior designs.